When testing a driving vehicle on a roller dynamometer, brake dynamometer, ABS dynamometer (hereinafter referred to as vehicle test bench), according to the prior art, the vehicle must be brought in straight-ahead position with respect to the vehicle test bench through the steering and then the steering wheel is to be kept in straight-ahead position to prevent a lateral drift of the driving vehicle during the test. In a vehicle test bench, this is effected by a driver at the end of the belt of a final vehicle assembly. The cause for the lateral drifting are lateral forces, which are exerted on the tires by the rollers and which arise in particular in steering angles of the tires. Due to the progressive technical development in vehicle components, it is possible to autonomously drive vehicles also in the production under certain boundary conditions. Therefore, there is the option to test vehicles driverless in vehicle test benches.
One option for implementing driverless testing is to make a positioning of the vehicle in straight-ahead position with respect to the vehicle test bench by a regulation process. The actuating variable is the steering (steering angle of the vehicle). A deviation from the target position can be recognized by means of the detection of the situation of the vehicle in the test bench. Because the vehicle runs with simulated speeds of up to 120 km/h in the vehicle test bench and the danger of a damage of the vehicle, the test bench and a hazarding of the operational personnel is to be avoided, a malfunction of the regulation process must be avoided. Such a malfunction could, for example, be based on a defective signal transmission in a wireless transmission of the control signals to the vehicle. Therefore, the test bench must be equipped with extensive safety technology. This safety technology is expensive. The same applies to the layout of the regulator circuit with an intervention with the steerage of the vehicle. This intervention would only have to be implemented for this type of testing since such automated intervention does not occur in normal driving operation of the vehicle.
Another option is documented in EP 2 166 332 A2. Here, a bar is fastened in a point beside the vehicle and is fastened with the other end to the steering wheel of the vehicle (through the opened side window). A lateral drifting of the vehicle thus effects a steering angle which counteracts the lateral drifting. The disadvantage of this option is that the connection with the steering wheel needs to be carried out by a workman. Furthermore, fastening of the steering wheel must be configured in such a way that it works for all types of steering wheels, ensures a secure connection with the steering wheel and nevertheless leaves no traces on the steering wheel.